My vote is for siberian ginseng. My experience is that is a life saver. It really helps me when my cortisol is too low and the effects are definitely felt within 30 minutes. The effects are tremendous to me. I'm not sure why I can feel it working so soon, but I have for the entire years that I have been dealing with this illness. It's the one supplement that has been working for me without any stimulation. Sometimes when I take licorice it stimulates me. Licorice is good though.